Records |
Author |
Nematollahi, P.; Neyts, E.C. |
Title |
Direct methane conversion to methanol on M and MN4 embedded graphene (M = Ni and Si): a comparative DFT study |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Applied surface science |
Abbreviated Journal |
Appl Surf Sci |
Volume |
496 |
Issue |
496 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
143618 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The ever increasing global production and dispersion of methane requires novel chemistry to transform it into easily condensable energy carriers that can be integrated into the chemical infrastructure. In this context, single atom catalysts have attracted considerable interest due to their outstanding catalytic activity. We here use density functional theory (DFT) computations to compare the reaction and activation energies of M and MN4 embedded graphene (M = Ni and Si) on the methane-to-methanol conversion near room temperature. Thermodynamically, conversion of methane to methanol is energetically favorable at ambient conditions. Both singlet and triplet spin state of the studied systems are considered in all of the calculations. The DFT results show that the barriers are significantly lower when the complexes are in the triplet state than in the singlet state. In particular, Si-G with the preferred spin multiplicity of triplet seems to be viable catalysts for methane oxidation thanks to the corresponding lower energy barriers and higher stability of the obtained configurations. Our results provide insights into the nature of methane conversion and may serve as guidance for fabricating cost-effective graphene-based single atom catalysts. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000488957400004 |
Publication Date |
2019-08-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0169-4332 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.387 |
Times cited |
2 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 3.387 |
Call Number |
UA @ admin @ c:irua:163695 |
Serial |
6294 |
Permanent link to this record |
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Author |
Nematollahi, P.; Neyts, E.C. |
Title |
Direct oxidation of methane to methanol on Co embedded N-doped graphene: Comparing the role of N₂O and O₂ as oxidants |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Applied Catalysis A-General |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
602 |
Issue |
|
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
117716-10 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this work, the effects of N-doping into the Co-doped single vacancy (Co-SV-G) and di-vacancy graphene flake (Co-dV-G) are investigated and compared toward direct oxidation of methane to methanol (DOMM) employing two different oxidants (N2O and O-2) using density functional theory (DFT) calculation. We found that DOMM on CoN3-G utilizing the N2O molecule as oxygen-donor proceeds via a two-step reaction with low activation energies. In addition, we found that although CoN3-G might be a good catalyst for methane conversion, it can also catalyze the oxidation of methanol to CO2 and H2O due to the required low activation barriers. Moreover, the adsorption behaviors of CHx (x = 0-4) species and dehydrogenation of CHx (x = 1-4) species on CoN3-G are investigated. We concluded that CoN3-G can be used as an efficient catalyst for DOMM and N-2O reduction at ambient conditions which may serve as a guide for fabricating effective C/N catalysts in energy-related devices. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000554006800046 |
Publication Date |
2020-06-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0926-860x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.5 |
Times cited |
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Open Access |
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Notes |
; This work was performed with the financial support from the Doctoral Fund of the Antwerp University (NO. BOFLP33099). All the simulations are performed on resources provided by the high-performance computing center of Antwerp University. ; |
Approved |
Most recent IF: 5.5; 2020 IF: 4.339 |
Call Number |
UA @ admin @ c:irua:171219 |
Serial |
6485 |
Permanent link to this record |
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Author |
Nematollahi, P.; Neyts, E.C. |
Title |
Identification of a unique pyridinic FeN4Cx electrocatalyst for N₂ reduction : tailoring the coordination and carbon topologies |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
Volume |
126 |
Issue |
34 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
14460-14469 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Although the heterogeneity of pyrolyzed Fe???N???C materials is known and has been reported previously, the atomic structure of the active sites and their detailed reaction mechanisms are still unknown. Here, we identified two pyridinic Fe???N4-like centers with different local C coordinates, i.e., FeN4C8 and FeN4C10, and studied their electrocatalytic activity for the nitrogen reduction reaction (NRR) based on density functional theory (DFT) calculations. We also discovered the influence of the adsorption of NH2 as a functional ligand on catalyst performance on the NRR. We confirmed that the NRR selectivity of the studied catalysts is essentially governed either by the local C coordination or by the dynamic structure associated with the FeII/FeIII. Our investigations indicate that the proposed traditional pyridinic FeN4C10 has higher catalytic activity and selectivity for the NRR than the robust FeN4C8 catalyst, while it may have outstanding activity for promoting other (electro)catalytic reactions. <comment>Superscript/Subscript Available</comment |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000859545200001 |
Publication Date |
2022-08-17 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.7 |
Call Number |
UA @ admin @ c:irua:191469 |
Serial |
7268 |
Permanent link to this record |
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Author |
Nematollahi, P.; Neyts, E.C. |
Title |
Distribution pattern of metal atoms in bimetal-doped pyridinic-N₄ pores determines their potential for electrocatalytic N₂ reduction |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Journal Of Physical Chemistry A |
Abbreviated Journal |
J Phys Chem A |
Volume |
126 |
Issue |
20 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
3080-3089 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Doping two single transition-metal (TM) atoms on a substrate host opens numerous possibilities for catalyst design. However, what if the substrate contains more than one vacancy site? Then, the combination of two TMs along with their distribution patterns becomes a design parameter potentially complementary to the substrate itself and the bimetal composition. In this study, we investigate ammonia synthesis under mild electrocatalytic conditions on a transition-metal-doped porous C24N24 catalyst using density functional theory (DFT). The TMs studied include Ti, Mn, and Cu in a 2:4 dopant ratio (Ti2Mn4@C24N24 and Ti2Cu4@N-24(24)). Our computations show that a single Ti atom in both catalysts exhibits the highest selectivity for N-2 fixation at ambient conditions. This work is a good theoretical model to establish the structure-activity relationship, and the knowledge earned from the metal-N-4 moieties may help studies of related nanomaterials, especially those with curved structures. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000804119800003 |
Publication Date |
2022-05-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1089-5639; 1520-5215 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
2.9 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 2.9 |
Call Number |
UA @ admin @ c:irua:189023 |
Serial |
7146 |
Permanent link to this record |
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Author |
Nematollahi, P.; Neyts, E.C. |
Title |
Linking bi-metal distribution patterns in porous carbon nitride fullerene to its catalytic activity toward gas adsorption |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Nanomaterials |
Abbreviated Journal |
Nanomaterials-Basel |
Volume |
11 |
Issue |
7 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
1794 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Immobilization of two single transition metal (TM) atoms on a substrate host opens numerous possibilities for catalyst design. If the substrate contains more than one vacancy site, the combination of TMs along with their distribution patterns becomes a design parameter potentially complementary to the substrate itself and the bi-metal composition. By means of DFT calculations, we modeled three dissimilar bi-metal atoms (Ti, Mn, and Cu) doped into the six porphyrin-like cavities of porous C24N24 fullerene, considering different bi-metal distribution patterns for each binary complex, viz. TixCuz@C24N24, TixMny@C24N24, and MnyCuz@C24N24 (with x, y, z = 0-6). We elucidate whether controlling the distribution of bi-metal atoms into the C24N24 cavities can alter their catalytic activity toward CO2, NO2, H-2, and N-2 gas capture. Interestingly, Ti2Mn4@C24N24 and Ti2Cu4@C24N24 complexes showed the highest activity and selectively toward gas capture. Our findings provide useful information for further design of novel few-atom carbon-nitride-based catalysts. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000676140500001 |
Publication Date |
2021-07-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2079-4991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.553 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.553 |
Call Number |
UA @ admin @ c:irua:180372 |
Serial |
8174 |
Permanent link to this record |
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Author |
Nematollahi, P.; Neyts, E.C. |
Title |
A comparative DFT study on CO oxidation reaction over Si-doped BC2N nanosheet and nanotube |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Applied surface science |
Abbreviated Journal |
Appl Surf Sci |
Volume |
439 |
Issue |
439 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
934-945 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this study, we performed density functional theory (DFT) calculations to investigate different reaction mechanisms of CO oxidation catalyzed by the Si atom embedded defective BC2N nanostructures as well as the analysis of the structural and electronic properties. The structures of all the complexes are optimized and characterized by frequency calculations at the M062X/6-31G* computational level. Also, The electronic structures and thermodynamic parameters of adsorbed CO and O-2 molecules over Si-doped BC2N nanostructures are examined in detail. Moreover, to investigate the curvature effect on the CO oxidation reaction, all the adsorption and CO oxidation reactions on a finite-sized armchair (6,6) Si-BC2NNT are also studied. Our results indicate that there can be two possible pathways for the CO oxidation with O-2 molecule: O-2(g) + CO(g) -> O-2(ads) + CO(ads) -> CO2(g) + O-(ads) and O-(ads) + CO(g) -> CO2(g). The first reaction proceeds via the Langmuir-Hinshelwood (LH) mechanism while the second goes through the Eley-Rideal (ER) mechanism. On the other hand, by increasing the tube diameter, the energy barrier increases due to the strong adsorption energy of the O-2 molecule which is related to its dissociation over the tube surface. Our calculations indicate that the two step energy barrier of the oxidation reaction over Si-BC2NNS is less than that over the Si-BC2NNT. Hence, Si-BC2NNS may serve as an efficient and highly activated substrate to CO oxidation rather than (4,4) Si-BC2NNT. (C) 2018 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000427457100112 |
Publication Date |
2018-01-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0169-4332 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.387 |
Times cited |
8 |
Open Access |
Not_Open_Access |
Notes |
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Approved |
Most recent IF: 3.387 |
Call Number |
UA @ lucian @ c:irua:150745 |
Serial |
4960 |
Permanent link to this record |